At present orally administered drugs are marketed as uncoated tablets, coated tablets, capsules, powders, granules, liquids, etc.
Orally disintegrating tablets and rapidly dissolving oral films are already on the market as medications that disintegrate in the mouth and are absorbed by the gastrointestinal tract. Among these a film-form preparation is useful from the standpoint of rapid dissolution.
A considerable amount of research has been conducted on such film-form preparations. For example, Patent Document 1 discloses a film-form preparation comprising hydroxypropyl cellulose or a mixture of hydroxypropyl cellulose and polyvinyl pyrrolidone, a tannin, and a drug.
Patent Document 2 discloses a film-form preparation comprising a drug and low-substituted hydroxypropyl cellulose.
Patent Document 3 discloses a film-form preparation comprising a drug and hydroxypropyl cellulose.
Patent Document 4 discloses a film-form preparation comprising a drug and hydroxypropyl cellulose.
Patent Document 5 discloses a tablet obtained by drying a liquid suspension wherein a drug and polyvinyl pyrrolidone are dissolved or dispersed in an organic solvent.
Patent Document 6 discloses that a film-form preparation containing a drug can also contain polymers that are water-soluble, water-swellable, water-insoluble, or a combination thereof.
Patent Document 7 discloses a film-form preparation containing drug particles.
However, the appearance and physical properties such as feel, etc., of film-form preparations are still unsatisfactory because the drugs contained in prior art film-form preparations exist almost entirely in a dissolved state or, even if they are in a solid state, they have been dissolved and recrystallized in the preparation to obtain the solid state. Even in film-form preparations wherein the drug is present in a solid state, it has been almost impossible to contain the drug therein in a particulate state, let alone control the particle size, because the drug is dissolved at least once during the manufacturing process.